Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds genuine context beyond that: it is a pre-flight introspection call whose output reflects current coverage and source state, which tells the agent the result can change over time and should precede other calls.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, tightly front-loaded with the usage trigger and then the return shape. No filler, though the second sentence's list is slightly dense and could be trimmed without loss.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a read-only, zero-required-parameter discovery tool with an output schema and rich annotations, the description covers trigger, ordering, and return scope adequately. The only real gap is the undocumented input parameters, which it assumes the agent will read from the schema.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0% and the description never mentions the `operation` or `capability` parameters or what they constrain. The enum values ('verify'/'assess', 'company_fr'/'import') are partly self-describing and both params are optional, which limits the damage, but the description does not compensate for the missing documentation.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource — discovering what FACTRAIL can verify/assess — and enumerates the shape of the return (capabilities, inputs, fields, sources, versions, limitations). It is clearly distinguishable from the action-oriented siblings (factrail_verify, factrail_assess, analyze_company) as the introspection entry point.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

"Use when you need to discover ... before calling another tool" plus "call first to inspect current coverage" gives explicit ordering guidance and a clear trigger condition. It lacks an explicit when-not-to-use clause, but the discovery framing makes the alternative (just call the verify/assess tool directly) obvious.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.